Which of the following coordination compounds is not likely to show optical isomerism?

Step-by-step solution

Optical isomerism is generally shown by octahedral complexes that lack elements of symmetry (plane of symmetry, center of symmetry). Let us analyze each complex: Option (1): [NiCl₂(en)₂] can exist in cis and trans isomeric forms. The cis form lacks a plane of symmetry and is optically active. The trans form has a plane of symmetry and is optically inactive. Therefore, the complex as a whole can show optical isomerism. Option (2): [Co(en)₃]³⁺ is an octahedral complex with three bidentate ligands. It lacks any plane